Display apparatus

Abstract

A display apparatus of the present invention includes scanning mirrors for scanning light emitted from a light source, a position sensor diode for detecting whether scanning by the scanning mirrors is normal or abnormal, a light intercepting shutter for intercepting light when the position sensor diode detects that the scanning is abnormal.

What is claimed is:  
     
       1. A display apparatus comprising: 
       a scanning mechanism for scanning light emitted from a light source, the scanned light being directed toward a location for a viewer's pupil;  
       a detector for detecting whether said scanning by said scanning mechanism is normal or abnormal; and  
       a controller for controlling the light such that the light does not reach the location for the viewer's pupil when said detector detects that the scanning is abnormal.  
     
     
       2. A display apparatus as claimed in claim  1 , further comprising an eyepiece optical system for projecting the scanned light to the location for the viewer's pupil. 
     
     
       3. A display apparatus as claimed in claim  2 , wherein said light emitted from the light source is modulated based on a video signal. 
     
     
       4. A display apparatus as claimed in claim  3 , wherein said scanning mechanism scans the light in two directions that are perpendicular to each other. 
     
     
       5. A display apparatus as claimed in claim  4 , wherein said eyepiece optical system provides the viewer with a picture as a virtual image. 
     
     
       6. A display apparatus as claimed in claim  1 , wherein said controller includes a light interceptor for intercepting the light and instructs said light interceptor to adopt a light intercepting condition when the scanning is abnormal. 
     
     
       7. A display apparatus as claimed in claim  6 , wherein said light interceptor is in a light intercepting condition when power is off. 
     
     
       8. A display apparatus as claimed in claim  6 , wherein said light interceptor is a liquid crystal shutter. 
     
     
       9. A display apparatus as claimed in claim  6 , wherein said light interceptor is a mechanical shutter. 
     
     
       10. A display apparatus as claimed in claim  6 , further comprising a splitter for splitting the scanned light in first and second directions. 
     
     
       11. A display apparatus as claimed in claim  10 , wherein said light interceptor is provided between said splitter and the location for the viewer's pupil. 
     
     
       12. A display apparatus as claimed in claim  10 , wherein said light split in the first direction is made incident on said detector. 
     
     
       13. A display apparatus as claimed in claim  12 , wherein said light split in the second direction is directed toward the location for the viewer's pupil. 
     
     
       14. A display apparatus as claimed in claim  1 , wherein said controller stops light emission from said light source when the scanning is abnormal. 
     
     
       15. A display apparatus as claimed in claim  1 , further comprising a light interceptor for intercepting the light, wherein the controller instructs the light interceptor to adopt a light intercepting condition when power is turned on, wherein the controller checks whether the light interceptor is in the light intercepting condition, and wherein the controller determines that an error has occurred if the light intercepting condition is not achieved after a predetermined number of checks. 
     
     
       16. A display apparatus as claimed in claim  1 , wherein the controller determines that an error has occurred if said scanning is determined to be abnormal a predetermined number of times. 
     
     
       17. A display apparatus as claimed in claim  1 , wherein the time required for one complete scan is compared with a permissible time for one complete scan to determine whether the scanning is normal or abnormal. 
     
     
       18. A display apparatus as claimed in claim  1 , wherein the time required for scanning between two points on the detector is compared with a permissible time for scanning between said two points on the detector to determine whether scanning is normal or abnormal. 
     
     
       19. A display apparatus as claimed in claim  1 , wherein a reference position on the detector is compared with a position of the scanned light on the detector after scanning for a predetermined period of time to determine whether the scanning is normal or abnormal. 
     
     
       20. A display apparatus comprising: 
       a light source for emitting light modulated based on a video signal;  
       a scanning mechanism for scanning the emitted light;  
       a light interceptor for intercepting the emitted light;  
       a detector for detecting whether scanning by said scanning mechanism is normal or abnormal; and  
       a controller for stopping light emission from said light source when said detector detects that the scanning is abnormal.  
     
     
       21. A display apparatus as claimed in claim  20 , wherein said light interceptor intercepts the light until the scanning is brought into a normal condition. 
     
     
       22. A display apparatus as claimed in claim  20 , wherein said light interceptor intercepts the light when said detector detects that the scanning is abnormal. 
     
     
       23. A display apparatus as claimed in claim  22 , wherein said light interceptor is in a light intercepting condition when power is off. 
     
     
       24. A display apparatus as claimed in claim  20 , wherein said light interceptor is a liquid crystal shutter. 
     
     
       25. A display apparatus as claimed in claim  20 , wherein said light interceptor is a mechanical shutter. 
     
     
       26. A display apparatus as claimed in claim  20 , further comprising an eyepiece optical system for projecting the scanned light. 
     
     
       27. A display apparatus as claimed in claim  26 , wherein said scanning mechanism scans the light in two directions that are perpendicular to each other. 
     
     
       28. A display apparatus as claimed in claim  27 , wherein said eyepiece optical system provides a viewer with a picture as a virtual image.